<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_外间距测试</title>
    <style>
        *{
            margin:0;
            padding:0;
        }
        /*.fu{*/
        /*    background-color:rgba(255,255,0.3);*/
        /*}*/
        .fu>div{
            width:100px;
            height:100px;
            background-color:rgba(0,0,255,0.3);
            margin:10px;
            border:2px solid #00f;
        }
    /*    .z1,.z2,.z3   */
    </style>
</head>
<body>
<div class="fu">
    <div class="z1">111</div>
    <div class="z2">222</div>
    <div class="z3">333</div>
<!--    dic默认高度为0，靠内容撑起来-->
</div>
</body>
</html>